Nanotechnology Commons^™

Nanoparticle Iron Based Catalysts For Clean Water And Other Applications, Shelby Lynn Foster

Graduate Theses and Dissertations

This dissertation explores the development, characterization, and application of iron-based catalysts for environmental remediation and energy generation. The research focuses on Fe-based nanomaterials for water purification, electrochemical ammonia production, and ethanol oxidation enhancement. The first section of the dissertation investigates the removal of water contaminants using nickel-iron (NiFe) bimetallic nanoparticles. Various NiFe ratios were synthesized and tested for their efficiency in degrading the azo dye (Orange G), with lower Ni content formulations achieving 80–99% dye removal within 60 minutes. Results show that changing the molar ratio of nickel to iron caused different removal rates, as well as the extent of …

Excitation Power Dependence Of Blinking In Copper-Indium-Sulfide Quantum Dots, Nicholas Chambers

Physics Undergraduate Honors Theses

Under continuous excitation, quantum dots exhibit random transitions between fluorescent ON states and non-fluorescent OFF states --- a phenomenon known as blinking. A physical description of the mechanism responsible for blinking that applies broadly to many types of quantum dots remains under debate. We study the blinking behavior of the non-toxic CuInS2 quantum dot, a system that has seen little investigation at the single-particle level. In particular, the optical properties of CuInS2 quantum are often improved by adding ZnS to the nanoparticles, but this addition leads to complex structural-optical property relationships that are even less understood. To probe the relationship …

Preparing Homogenous Composites Of Collagen And Cellulose Nanocrystals For Tissue Engineering Research, Zachary Stanley

Biological and Agricultural Engineering Undergraduate Honors Theses

Advancements in medicine and our understanding of stem cells have led to a greater emphasis on further developing research focused on tissue engineering. This research has led to the rise of both two-dimensional and three-dimensional scaffolds that can be utilized to repair bone, skin, vascular, and potentially even nervous tissue. One of the prominent compounds used in modern scaffolds is collagen-based hydrogels due to their low antigenicity and ability to provide structure to cells. There is potential to further improve upon this three-dimensional scaffold by incorporating cellulose nanocrystals (CNCs) into a composite hydrogel with collagen. The addition would increase the …

Multifunctional Programmable Self-Assembled Nanoparticles In Nanomedicine, Yoshie Sakamaki

Graduate Theses and Dissertations

Developing methodologies to control the architecture of nanoparticles (NPs) at the atomic level prevents their inhomogeneity and leads to a variety of expected functions. Rationally designed nanoparticles can either be programmed or crystallized structures into pre-determined structures achieving tunable particle pore size and physiochemistry. In this dissertation, two broad classes of multifunctional nanoparticles are developed, metal-organic frameworks and DNA-NP aggregates.

Metal-organic frameworks are a novel class of highly porous crystalline materials built from organic linkers and metal cluster-based secondary building units. However, applications in bioremediation have not been developed very well especially in applications regarding drug delivery systems (DDS). The …

Development Of Biomaterials For Drug Delivery, Raquel De Castro

Graduate Theses and Dissertations

Drug delivery systems (DDS) have highly evolved in the last decades with the development of hydrogels and nanoparticles. However, high systemic uptake, side effects, low bioavailability, and encapsulation efficiency continue to be a major hurdle faced by such DDSs.

Nanoparticles and hydrogels can be specifically designed for targeted DDSs to mitigate some of the problems. This dissertation aimed to design two DDSs for ocular drug delivery and one for cancer treatment. The first project sought to develop chitosan nanoparticles (Cs-NP) using PEGDA as a copolymer to encapsulate gentamicin (GtS) for ocular drug delivery. Cs-NPs contain positive charges that can interact …

Customization Of Titanate Nanofiber Bioscaffolds, Jared Hopkins

Biomedical Engineering Undergraduate Honors Theses

In the field of orthopedic devices implant loosening is a major issue resulting in the majority of device failures. These failures result in the need for costly secondary procedures. To reduce device loosening an improved method of tissue anchoring is required. A previously studied titanate nanofiber bioscaffold has been shown to be safely implantable and to contribute to the differentiation of mesenchymal stem cells to osteocytes. Through the customization of both physical and chemical characteristics this titanate nanofiber bioscaffold was fabricated as a potential means to enhance tissue anchoring for use with orthopedic devices. This customization was enabled by acoustic …

Hybrid Nanostructured Textile Bioelectrode For Unobtrusive Health Monitoring, Pratyush Rai

Graduate Theses and Dissertations

Coronary heart disease, cardiovascular diseases and strokes are the leading causes of mortality in United States of America. Timely point-of-care health diagnostics and therapeutics for person suffering from these diseases can save thousands of lives. However, lack of accessible minimally intrusive health monitoring systems makes timely diagnosis difficult and sometimes impossible. To remedy this problem, a textile based nano-bio-sensor was developed and evaluated in this research. The sensor was made of novel array of vertically standing nanostructures that are conductive nano-fibers projecting from a conductive fabric. These sensor electrodes were tested for the quality of electrical contact that they made …

Design And Fabrication Of Nanofluidic Systems With Integrated Sensing Electrodes For Rapid Biomolecule Characterization, Taylor Bradley Busch

Graduate Theses and Dissertations

A transparent nanofluidic system with embedded sensing electrodes was designed and fabricated by integrating Atomic Force Microscopy (AFM) nanolithography, Focused Ion Beam (FIB) milling and metal deposition, and standard microfabrication processing. The fabrication process started with the evaporation of chrome/gold (Cr/Au) onto a Pyrex 7740 wafer followed by photolithography and wet etching of the microchannels. The wafer was patterned a second time to form Au microelectrodes with 15-45 micrometer separation gaps in the nanochannel region. Sensing electrodes (up to one micron wide) were then deposited using FIB to bridge the gaps. The nanochannels were realized through both AFM nanolithography and …

Design And Fabrication Of Nanofluidic Systems For Biomolecule Characterizations, Orain Ansel Hibbert

Graduate Theses and Dissertations

Nanofluidic channel systems were designed and fabricated by combining MEMS microfabrication with AFM nanolithography. In the fabrication process flow, photolithography was first utilized to pattern microfluidic channels and reservoirs on a 4" Pyrex substrate. Subsequently, atomic force microscopy (AFM) based nanolithography was used to mechanically fabricate nanochannels to connect the microreservoirs which formed the inlet and outlet of the nanofluidic system. A Tap190 Diamond-Like Carbon (DLC) AFM tip with a force constant of 48 N/m and a radius of less than 15 nm was used as the nanolithography tool. The resultant nanochannel ranges from 20 to 80 µm in length …

Synthesis Of Zinc Oxide Nanorods And Use In Biosensor Applications, Anishkumar Manoharan

Graduate Theses and Dissertations

The main aim of this research was to develop a nanorod based biosensor for biomedical applications. In this project I use zinc oxide nanorods as the bio-material for biosensor. I fabricated these nanorods using a solution-based technique. Initially I coated a zinc oxide seed layer as the base. This seed layer was then annealed at 350 degrees for almost 1 hour. As a next step, interdigitated electrodes were fabricated on the top of the seed layer using a lift off process. The zinc oxide nanorods were then grown at 90 degrees for almost 4 hours along the electrodes. In this …

Raman Spectroscopy Of Titania (Tio2) Nanotubular Water-Splitting Catalysts, F. D. Hardcastle

Journal of the Arkansas Academy of Science

The phase composition of nanotubular TiO2 films was correlated with photoelectrochemical activity as a function of O2-annealing temperature. TiO2 nanotubes have been shown to be more efficient than polycrystalline TiO2 for the photocatalytic splitting of water. Raman spectroscopy was used to identify and quantify the amorphous and crystalline TiO2 phases. The amorphous TiO2 nanotubular array was found to consist of TiO6 8- octahedra having the same average structure as those present in the anatase and rutile phases of TiO2. Results show that the anatase-to-rutile transformation on Ti metal initiates at much lower temperatures compared to polycrystalline TiO2 and this is …